FLOATING. 



393 



are three iron rods one inch in girth supported by bars 2 inches 

 in girth from the broad-gauge sleepers. 



This boorn cost Es. 1150, including Es. 500 for wire ropes, 

 which last for many years ; it is annually removed before the 

 July monsoon, and replaced in October. About 400,000 sleepers 

 and scantling are stopped by it annually and made-up into rafts 

 at Daghpathar. Tr.] 



(b) Modes of using Booms. According to the strength of the 

 stream, the purpose for which they are erected, but above all on 

 account of their suita- 

 bility for any particular 

 locality, various kinds of 

 booms are used. Here, 

 in the first place, a dis- 

 tinction must be made 

 according as the booms 

 are used, either to stop 

 all the wood floating 

 in a stream (terminal 

 booms), or to divert it 

 into a side-channel 

 (lateral booms) ; it must 

 be considered, secondly, 

 what steps may be 

 taken to reduce the 

 pressure on booms and 

 prevent them from 

 breaking. 



Fig. 21)6. Terminal boom at Passaii. 



Trrniinal 



Terminal booms, in- 

 tended to stop all the 

 wood floating in a stream, are erected either transversely or 

 obliquely across a stream, the former being termed straight 

 and the latter oblique booms. Booms may run in a broken 

 line, or be arranged so that a quantity of floating wood may 

 be collected and taken away from the boom. 



Straight booms are made chiefly on streams with a slight 



